Dithiocarbamates



Patented Jan. 12, 1937 UNITED STATES PATENT OFFICE DITHIOCARBAMATES Joy G. Lichty, Akron, Ohio, assignor to Wingfoot Corporation, Wilmington, Del., a corporation of Delaware No Drawing. Application April 5, 1932, Serial No. 603,454

'7 Claims. (01. 260-9911) This invention relates to the vulcanization of rubber. More particularly, it relates to a method of accelerating the processes of vulcanization by incorporating in the unvulcanized stock certain chemical compounds which not only are comparatively easy to prepare but also impart desirable physical properties to the vulcanized product. The compounds with which the invention deals may be described as derivatives of the dithiocarbarnic acids. A

The following type formula illustrates the com- In the preparation of carboxy methyl di(diethyl dithiocarbamate), an aqueous solution containing 1 mol. of sodium diethyl dithiocarbamate and mol. of ammonium dichloroacetate is pounds which the invention concerns: heated at 50 degrees C. on a water bath for 1% 15 0 hours. It is then chilled with ice and acidified ll with hydrochloric acid, giving a dark-colored i M oil. The oil is removed by means of a separatory v S n n funnel, after which the carbamate is extracted In this formula, Y represents either the group with diethyl ether from the aqueous layer- The 20 R, total yield of the dry product is in the neighborhood of 64%. For the preparation of carboxy methyl di(pentamethylene dithiocarbamate) an aqueous H solution containing A; mol. of ammonium di- 25 (R and bemg aryl or aralkyl radichloroacetate and mol. of sodium pentamethy- Gals) or heterocychc radmal Such as lene dithiocarbamate is heated on a steam bath CHr-CH: for a short time, much hydrogen sulfide being I CH2 liberated in the meanwhile. The liquid is acidified with hydrochloric acid. There results a 30 CHPCH light brown solid which decomposes on melting. The letter 11. represents one or more, R stands for The reactions for this preparation may be excarbon or carbon and hydrogen, and M 'reprepressed as follows:

= I 2C H1oN-OSSNa+ClaGHOOONH4--)(CsHwN-CSS);OHCOONH+2NaC1 35 sents hydrogen, a metal, an alkyl, aryl or aralkyl radical, or a salt-forming radical such as the 40 ammonium and substituted ammonium groups, of

which the following are examples:

As illustrating the preparation of these compounds there may be mentioned the preparation of carboxy-methyl di(dimethyl dithiocarbamate). In preparing this material, an aqueous solution containing 4 mol. of ammonium dichloroacetate and mol. of sodium dimethyl dithiocarbamate is heated on a water bath at 50 degrees 'C. for of an hour, after which it In the preparation of carbethoxy methyl di(dimethyl dithiocarbamate) a mixture containing mol. of ethyl dichloroacetate, mol. of sodium dimethyl-dithiocarbamate in aqueous 55 solution and 200 cc. acetone is refluxed for one half hour. The product is cooled and the solid Carbethoazy methyl di(dimethyl dithz'ocarbamate) removed by filtration. The yield is about 66%. 15 250 52 875 s 20 When recrystallized from a solution of chlorog8 g2 3g form and alcohol, the product melts at 178 de- 40 250 172 720 as 154 5 rees C. The reactions are as follows: CH5 s v 01 r CH5 s II ll 2 NCSNa+ -/OH-COOC1H5-- N-CS 0H-COOC1H +2NaC1 on; 01 CH5 10 In ,the preparation of the diphenylguanidine Diphenylguanidine salt of carboxy methyl di(disalt of carboxy methyl di(dimethyl dithiocarmethyl dithiocarbamate) bamate), a mixture of 14.9 grams of carboxy methyl di(dimethyl dithiocarbamate) and 10.6 v 5 260 114 885 12 31 15 grams of diphenylguanidine are dissolved in 55 cc. Z3 of alcohol. The solvent is removed by long 20 .260 202 680 52 standing in the open, finally allowing the mixture to remain over calcium chloride in a vacuum These compounds, which are new in themdesiccator for 48 hours. The yield is quantitaselves, possess valuable properties as accelerators 20 tive. The reaction proceeds as follows: of vulcanization. It will be understood that the CH3 s CH5\ i iii NH-CH5 NCS}OHCOOH+CQHE-NH--)[ N-os]oH-ooo1 q=o CH3 2 CH3 5 H LIT-03H; sHdIT H These compounds were tested as accelerators specifically described details of the invention as o of vulcanization by incorporating them into a herein given may be varied within comparatively rubber composition of the following formula: wide limits Without departing from the inventive concept and that it is. desired to embrace within Parts the scope of this invention such modifications and Rubber .(gxtracted pale. crepe) g-g changes as may be necessary to adapt it to vary- 0X1 6 ing conditions and uses. It is intended that the t -"7; -"f patent shall cover, by suitable expression in the Steanc appended claims, whatever features of patentable Accelera' W novelty reside in the invention. 'After vulcanization, h sical tests were run with What is claimed is: results indicated p y maliegjarboxy methyl di(dimethyl dithiocarba- 40 2. A compound having the formula Cure 7 Stress kgslcm at O 'r '1 El Timein Temp. ens! 9 one 500% 700% Y- 3-s), oE-coH 45 Mins. F. elong. elong.

v p 1 wherein Y is a tertiary aliphatic amino rou Carboxy methyl di(dim ethyl dzthz'ocarbamate) A compound having the f ul g p n I (Y- -s)1=oHooH wherein Y is an aliphatic amino group.

4. A compound having the formula 55 El) 10 260 98 895 13 33 ig )=OH COH 15 260 119 855 14 47 20 260 141 805 21 75 v 35 260 116 675 34 wherein Y is a dialkyl amino group. 60

s 5. Ammonium carboxy methyl di( dimethyl di- C'arboazy methyl di(pentamethylene dithiocarthi b t bamate) 6. A compound having the formula (Y-CS 2=CHCONH4 15 260 73 905 11 25 5 I] II 65 20 260 101 860 15 41 S 35 260 129 805 20 68 V 5 260 780 25 90 wherein Y is a tertiary aliphatic amino group. g

7. The compounds having the formula Carbethoxy methyl di dzethyl dzthiocarbamate) 70 ll 20 260 75 900 11 2s fi )=CH C OH 25 260 104 845 15 43 40 260 148 775 25 94 60 260 760 32 126 wherein Y is a tertiary amino group. O 

